Birds as Bioindicators of Radioactive Contamination and Its Effects

Birds are regarded as excellent bioindicators of anthropogenic environmental change, including changes due to the release of toxicants into ecosystems. Consistent with this, birds are among the best-studied groups of organisms under conditions of radioactive contamination. This includes the study of radionuclide transfer to their bodies as well as the estimation of the associated radiation doses. This paper reviews the literature on the use of birds in studies of radiation exposure, and the effects of low-dose, low-dose rate ionizing radiation on birds. A variety of effects have been documented on birds exposed to ionizing radiation under ecological conditions. These studies, mostly in the context of the nuclear accidents of Chernobyl and Fukushima, are organized based on the level of biological organization analyzed, from molecular and cytological studies, to physiological, behavioral and life-history effects. We also discuss the translation of these effects into consequences at the level of populations and communities, and examine how avian species vary in their exposure and susceptibility. We conclude by suggesting future avenues of research, including the development of molecular and –omics biomarkers that will increase the sensitivity of retrospective dosimetry, and aid the detection of low-dose effects.